Welding safety

THE US Mine Safety and Health Administration has issued a program protection letter regarding the safe use of welding machinery on longwall mining systems.
Welding safety Welding safety Welding safety Welding safety Welding safety


Donna Schmidt

The communication, effective March 13, states welding cables must not be permanently attached to the welding machine when no welding is being performed.

The agency released a series of implementations to ensure that all equipment is properly operated and that all hazards to the miner are avoided.

Those regulations include the following:

When welding is being conducted, two single conductor cables or a two-conductor cable must be used and the machine’s grounded work lead must be connected at the point where the welding is being done;

Welding connectors and pigtails are to be designed, installed and maintained so that no conductors or parts are exposed. Additionally, all are to be MSHA certified;

Mining is to be suspended while welding is being conducted and specific precautions must be taken with regard to where the welding machine is located;

Any welding cable located along the face of the longwall must be de-energised and locked out when welding is not being conducted;

A qualified person must conduct an inspection of the entire welding cable prior to connecting and energising the welding machine to verify no parts or conductors are exposed;

A qualified individual must verify that methane levels are below 1.0 volume per centum beneath the panline and feeders as well as throughout the welding area before welding can commence. Levels must also be checked near portable, stand-alone welding machines; and

Procedural instructions for this must be included in mine operators’ training plans and must be addressed during required training time.

“In promulgating this standard, MSHA recognised that welding on some equipment, such as longwall mining systems, may be necessary in areas where permissible equipment is normally required,” the agency noted in the PPL.

It added that the measure is being taken for the protection and safety of the miner: “MSHA also recognised that welding machines and welding methods are not permissible. Consequently, the standard permits these types of activities to be performed under certain controls to prevent fires and explosions where welding is taking place.”